True, I don't know what percentage of contributions to PHP are made while in employee of a corporation funding said contributions, but there are commercial supporters of PHP out there. I'm surprised how few people don't know that Zend exists.
The original comment just struck me oddly because I've come to assume that a large portion of the software that I use regularly was originally developed as an amateur project, or by amateurs.
I'm not sure where you're heading with this. I was trying to tell the parent comment that arguing against 'amateur' coders writing php is the same as the Linux kernel was factually incorrect.
If you wanted to get that point across, you could have said it much better. Your analogy to the PHP language itself is completely false and not in any way useful.